Potato and leek soup give us one of the great flavor and texture combinations in all the culinary arts. The leek and potato pairing starts with the creamy, starchy potato and enhances it with the fresh, pungent, oniony flavor of the leeks. Meanwhile, the leeks contribute some crunch to the smooth texture of the potato. All in all, it's a great, satisfying soup.
When you're working with leeks, it's important to make sure that you rinse out any dirt and grit that can sometimes be deposited within the concentric tubes that make up the stalk. To do that, it's often necessary to slice the stalk lengthwise so that you can rinse the dirt out from between the layers.
Alternately, you can slice the leek into sections and then rinse them individually. This method has the benefit of preserving the rings of the leeks, which doesn't matter much to the extent that the leeks are being puréed anyway. BUT: You'll see in step 5 that we set aside some of the sautéed leeks to use as a garnish. And the intact rings would make a nice garnish, so that's something to think about.
By the way, you can substitute crème fraîche for the cream if you want to maximize the sensation of eating a bowl of baked potato soup. It's like sour cream, only it won't break when it's added to hot soup the way sour cream will. And you don't have to heat the crème fraîche before adding it. Just stir it directly into the soup before seasoning and serving.
- ½ lb leeks, thoroughly rinsed
- 2 to 3 medium Russet (or other starchy) potatoes
- 3 to 4 slices of bacon, diced
- 1½ tablespoons unsalted butter
- 1 medium onion, peeled and roughly chopped
- 1 clove garlic, peeled and crushed
- ½ cup dry white wine
- 1-quart vegetable broth or stock
- Kosher salt, to taste
- Ground white pepper, to taste
- ¼ cup heavy cream, warmed
- Cut leeks into (roughly) same-sized pieces, about ½ inch to 1 inch thick, depending on diameter. We just want the pieces to be of uniform size so that they cook evenly, but they don't have to be cut precisely.
- Peel the potatoes and cut them into pieces about the same size as the leeks.
- In a heavy-bottomed soup pot, heat the butter over a low-to-medium heat. Add the bacon and onion, and cook slowly until most of the fat has rendered out, and the bacon is lightly golden brown but not burnt. Remove the bacon from the pan and set aside on paper towels to drain.
- Add the onion, garlic, and leeks and cook for 2 to 3 minutes or until the onion is slightly translucent, stirring more or less continuously. Add the wine and cook for another minute or two or until the wine seems to have reduced by about half.
- Add the stock and the potatoes. Increase the heat to medium-high and bring to a boil. Then lower the heat and simmer for 15 minutes or until the potatoes are soft enough that they can easily be pierced with a knife. Don't let them get mushy, though.
- Pull out some of the cooked leeks and set it aside. You can dice it up a little bit smaller and use it as a garnish.
- Remove the soup from the heat and purée using an immersion blender, or in a regular blender. If you're using a regular blender, it may be necessary to work in batches, so that you don't overfill the pitcher. Start on a slow speed with the lid slightly ajar to vent any steam, then seal the lid and increase the speed.
- Return the puréed soup to pot and bring to a simmer again, adding more broth or stock to adjust the thickness if necessary.
- Stir in the cream along with the reserved bacon, season to taste with Kosher salt and white pepper. Garnish with the reserved diced leek and serve right away.